This study deals with the issue of democratization in Latin America during the 20th century, and in particular the role of the left in this process. The purpose of this study is to empirically analyze the role of the left as a political actor in the process of democratization toward the deepening of the democratic rule in Latin America. The research questions are: what role did the left have in the transitions to electoral democracies during the 20th century in Latin America? Why did the left have the role it had in the transitions? How does the left’s view of democracy affect the transition to electoral democracy, and the further democratization to deepen democratic rule? What structural constraints affect the left’s ability to deepen democratic rule?A comparative qualitative method and different theoretical concepts of democracy, democratization, elite perspective, mobilization and organizations have been used, and examples from different Latin American cases are given. One empirical conclusion is that the role of the left in the transitions to electoral democracies varies from participation with active left leaders, collective left actions, to not have any significant role at all. A second empirical conclusion is that in cases where left wing governments have tried to enforce a model of participatory democracy, the result has been “ coup d’état” or rebellions conducted by military forces and supported by the economic elite and the United States of America. In other cases when left parties in government instead have remained within the framework of an elite democracy, the result has rather been stabilization of the liberal democratic rule.The main theoretical conclusions are as follows: the theoretical discussion about democratic consolidation and the deepening of democracy have to consider that different actors’ (in this study the left) preferences for various models of democracy differ; the actors’ view of democracy matter in the game of democratic development and democratic consolidation; and the relations between the elite actors’ preferences for different models of democracy determine the outcome of a specific form of democratic model (in this study electoral democracy, liberal democracy or participatory democracy).